Recently, as energy consumption is increased, solar cell apparatuses to convert the solar light into electrical energy have been developed.
In particular, a CIGS-based solar cell, which is a PN hetero junction apparatus having a substrate structure including a glass substrate, a metallic back electrode layer, a P-type CIGS-based light absorbing layer, a high-resistance buffer layer, and an N-type window layer, has been extensively used.
Various studies and researches have been performed to improve electrical characteristics of the solar cell, such as low resistance and high transmittance.
Meanwhile, since a material of a back electrode layer is deposited on the entire surface of a support substrate when forming the back electrode layer, even a portion of a bus bar to be connected with a connecting member makes contact with the back electrode layer. Thus, a shunt path may be caused and the reliability of the solar cell apparatus may be reduced.